Composite strand material



1\Iw.3o,1943.y w. M. CAM'P y, Q 2,335,644

COMPOS ITE STRAND MATERIAL Filed May 27, 1942 A a INVENTR. I/////am M Camp ATTOHIVEYJ Patented Nov. l30, 1943 JOMPOSITE STRAND MATERIAL William liI. Camp, Glen Ridge, N. J., assignor to The Clark Thread Company, Newark, N. J., a` corporation of New Jersey Application May 27. 1942, serial No. 444,731 z claims. (ci. isi-14o.)

'This invention relates to composite strand inaterial adapted for use as thread cord and the like.

The problem to which the invention is primarilyy directed is the conversion of thread or cord made from abrasion-susceptible material into strand materialresistant to abrasion and possessing generally properties enabling it to withstand successfully the demandsand criteria of a successful sewing thread.

Wrapped core is then subjected to a treatment to impregnate and coat the wrapping and bond it to the core by means of a film-forming adhesive 3. For this purpose, flexible film-forming adhesives in general may be used. It is necessary for the wrappings to be bonded properly to the core, otherwise they slip and pile up in one place on the core and cause failure in sewing. While, as

n stated, flexible nlm-forming adhesive in general Yarn made of glass and certain organic -synv thetic fibers, e. g., those. made from vinyl polymers, have valuable properties and numerous at.- tempts have been made to manufacture thread cord and the like therefrom. They also possess, however, certain disadvantages which make it diiiicult to utilize such yarns in making sewing Y thread. y The chief disadvantage is brlttlene'ss andv Asusceptibility to abrasion. l

Sewing thread is subject to very severe conditions in use. For example. it passes through the eye of the needle at a vsharp angle and in frictional contact with the edges of the hole. It must therefore be highly flexible and resistant to abrasion. Threads made of glass yarn, for example, are, as such, not entirely satisfactory because of their susceptibility to abrasion and brittleness. In other words, their resistance to abrasion is very low and their brittl'eness very high.

The principle of the present invention will be 'illustrated by reference to the accompanying drawin. in which: v

Fig. 1 shows a thread. cord or the like made from glass yarn; -f

Fig. 3 shows this cord provided with a wrapping of cottonsilk or other abrasion resistance material;

Fig. 5 shows the wrapping coated and impregnated and bonded to the core by means of a nlmforming adhesive:

F18. 'l .shows the product of liig. 5 provided y with s friction reducing coating:

Figs. 2. 4. 8, and. 8 are transverse sections corresaonding to Figs. l, 3, 5, and 7, respectively: Van

liig. 9 is a longitudinal sectional view of the product illustrated in Fis'. '7.

The core I istwisted from glass or other yarn so low in abrasion resistance as to be incapable of use per seas 4sewing material. This core is thenprovided with wrappings 2, e.'g., of the di agonai type of strand material highly resistant to abrasion, e. g.. cotton, silk, nylon. .The

may be used, those which are light colored and do not interfere with desired dyeing operations are preferred, e. g., latex, polyvinyl alcohol, hydrolized cellulose acetate, starch.

The coating, impregnation and bonding of the `wrapping to the core may be accomplished by passing the wrapped core through a bath' of the adhesive dissolved or dispersed in asuitable menstruum, aqueous or'non-aqueous, depending on the nature of the adhesive.. Those specifically above listed are dispensible in an aqueous medium.

Attempts to solve the problem by relying on such film-forming substances applied tothe core without the wrapping provide some improvement but are not satisfactory .to produce thread for sewing all types of fabrics. It is necessary to use both the wrapping and adhesive" and to' bond the former securely to the core in order to get sufiicient abrasion resistance and strength to meet this necessary criteria.

Finally, in order to reduce friction, a frictionreducing nish coat I is preferably applied, e. g.,

a wax.

I claim:

l. Composite strand material adapted for use as thread, cord and the like comprising score of twisted glass yarn: a wrapping'y of abrasionresistant strand material covering said core; said wrapping being impregnated and coated andv bonded to the core with a nlm-forming adhesive,

and a friction-reducing coating on thesurface of said coated and impregnated wrapping.

2. Composite strand material adapted for use as thread. cord and the like comprising a core of twisted yarn susceptible to abrasion when used in sewing; a wrapping of abrasion-resistant 'strand material covering said core; said wrapping being impregnated and coated and bonded to the core with a film-forming adhesive, and al friction-reducing coating on'the surface of said coated vand impregnated wrapping.

' IWILLIAM M. cAMP. 

